Telegraph 's lead editor, admitting awful blunder, is one wheeled out for retirement? (7,3)

'one wheeled out for retirement?' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.

'telegraph 's lead editor admitting awful blunder' is the wordplay.
'telegraph 's' becomes 't' (I can't justify this - if you can you should give a lot more credence to this answer).
'lead' says to put letters next to each other.
'editor' becomes 'ed' (abbreviation).
'admitting' is an insertion indicator (admit can mean to welcome in or accept).
'awful' indicates anagramming the letters.
't'+'ed'='ted'
'blunder' anagrammed gives 'rundleb'.
'ted' enclosing 'rundleb' is 'TRUNDLE-BED'.

'is' acts as a link.

Can you help me to learn more?